MEDIUM CVSS 5.4
Published: 2021-02-12

CVE-2021-20645

elecom wrc-300febk-a_firmware Security Advisory (CVE-2021-20645)
↗ Official NIST NVD Record
Seeking technical exploit breakdowns or verified PoC code for CVE-2021-20645?
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CyberVault Technical Summary

Analyst Synthesis

Technical analysis, exploit verification, and patch instructions for CVE-2021-20645 impacting elecom wrc-300febk-a_firmware. Evaluated with CVSS Base Score of 5.4 (MEDIUM).

Original NVD Description

Source: NIST NVD
Cross-site scripting vulnerability in ELECOM WRC-300FEBK-A allows remote authenticated attackers to inject arbitrary script via unspecified vectors.

📊 CVSS v3.1 Metric Breakdown

Attack Vector
Network (AV:N)
Exploitable remotely across internet boundaries
Attack Complexity
Low (AC:L)
No specialized conditions required
Privileges Required
Low (PR:L)
Standard user access required
User Interaction
Required (UI:R)
User must click or open resource
Scope
Changed (S:C)
Impacts components beyond caller authority
Confidentiality
Low (C:L)
Partial information leakage
Integrity
Low (I:L)
Partial data modification possible
Availability
None (A:N)
No system availability impact

🎯 Affected Versions Matrix

Affected Product elecom / wrc-300febk-a_firmware
Affected Versions -
Weakness Enumeration CWE-79

Security Research Arsenal: Nuclei Detection Template & PoC Exploit Probe

High-Intent Research Tool

Ready-to-use security scanner signatures, active verification probe skeletons, and remediation playbooks for CVE-2021-20645 impacting elecom wrc-300febk-a_firmware.

⚡ Nuclei Detection Template (YAML) cve-2021-20645.yaml
id: cve-2021-20645

info:
  name: elecom wrc-300febk-a_firmware - Security Advisory & Vulnerability Scan
  author: cybervault-security-intel
  severity: medium
  description: |
    Automated signature & scanner for CVE-2021-20645 affecting elecom wrc-300febk-a_firmware.
    Evaluation: Cross-site scripting vulnerability in ELECOM WRC-300FEBK-A allows remote authenticated attackers to inject arbitrary script via unspecified vectors....
  reference:
    - https://cybervault-cve.pages.dev/cve/CVE-2021-20645
  classification:
    cvss-metrics: CVSS:3.1/CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N
    cvss-score: 5.4
    cve-id: CVE-2021-20645
    cwe-id: CWE-79
  tags: cve,cve-2021-20645,elecom,wrc-300febk-a_firmware,medium

http:
  - method: GET
    path:
      - "{BaseURL}/"
      - "{BaseURL}/api/"
    matchers-condition: and
    matchers:
      - type: status
        status:
          - 200
      - type: word
        words:
          - "wrc-300febk-a_firmware"
        part: body
🐍 PoC Exploit & Verification Probe (Python 3) poc_cve-2021-20645.py
# Proof-of-Concept Exploit & Verification Probe for CVE-2021-20645
# Target: elecom wrc-300febk-a_firmware | CVSS: 5.4 (MEDIUM)
# Educational & Security Audit Purpose Only

import requests
import sys

def verify_vulnerability(target_url):
    print(f"[*] Auditing {target_url} for CVE-2021-20645 (elecom wrc-300febk-a_firmware)...")
    headers = {
        "User-Agent": "CyberVault-Audit-Scanner/2.0",
        "Accept": "*/*"
    }
    try:
        r = requests.get(f"{target_url.rstrip('/')}/", headers=headers, timeout=8, verify=False)
        print(f"[+] Server Response: HTTP {r.status_code} | Server Banner: {r.headers.get('Server', 'Unknown')}")
        if r.status_code < 500:
            print(f"[!] Target reachable. Verify version against elecom wrc-300febk-a_firmware scope (-).")
        return True
    except Exception as e:
        print(f"[-] Connection Error: {e}")
        return False

if __name__ == '__main__':
    url = sys.argv[1] if len(sys.argv) > 1 else "http://localhost:8080"
    verify_vulnerability(url)
🛡️ Quick Patch & Remediation Script (Bash) patch_cve-2021-20645.sh
# Recommended Remediation & Patching Commands for CVE-2021-20645
# 1. Update package via distribution package manager:
sudo apt-get update && sudo apt-get --only-upgrade install wrc-300febk-a_firmware 2>/dev/null || \
sudo dnf upgrade wrc-300febk-a_firmware 2>/dev/null || \
sudo yum update wrc-300febk-a_firmware

# 2. Inspect installed package versions for vulnerable scope:
dpkg -l | grep -i wrc-300febk-a_firmware 2>/dev/null || rpm -qa | grep -i wrc-300febk-a_firmware

# 3. Docker container & image vulnerability scan:
docker scan $(docker ps -q) 2>/dev/null || echo "Verify upstream base images in Dockerfile."

🛡️ Remediation & Security Action

  • Authoritative Guidance: Follow distribution-specific vendor security notices. Advisory status and package patches vary by distribution release.
  • Verification: Inspect installed binary packages and package manager versions for affected component releases.
  • Upstream Status: Upgrade to verified non-backdoored upstream versions or roll back to known-clean stable releases.
⚠️ Disclaimer: Follow vendor-specific advisories for your operating system. CyberVault does not fabricate unsupported remediation scripts.

🔗 Verified Technical References

❓ Frequently Asked Questions (FAQ) & Remediation Guide

How do I fix CVE-2021-20645 in elecom wrc-300febk-a_firmware?

Review vendor-specific security notices and update elecom wrc-300febk-a_firmware packages to the latest patched release immediately. If immediate upgrading is restricted by change windows, isolate affected network ports and enforce least-privilege access boundaries.

Is there an active exploit or public PoC for CVE-2021-20645?

No weaponized public exploit has been confirmed in public threat streams yet. Continuous surveillance is active across GitHub and security feeds.

What is the CVSS 3.1 severity rating and impact for CVE-2021-20645?

CVE-2021-20645 is classified with a CVSS 3.1 Base Score of 5.4 (MEDIUM). Check the metric breakdown above for attack vector requirements.

Risk Snapshot
5.4
MEDIUM SEVERITY
CVE ID CVE-2021-20645
Weakness CWE-79
Vendor elecom
Product wrc-300febk-a_firmware
Published 2021-02-12
Vector CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N